This invention relates to the production of poly(arylene sulfide sulfone)s. In one aspect, this invention relates to the production of poly(phenylene sulfide sulfone). In another aspect, this invention relates to the production of poly(arylene sulfide sulfone)s exhibiting high molecular weight. In a further aspect, this invention relates to the production of poly(phenylene sulfide sulfone) exhibiting high molecular weight.
Poly(arylene sulfide sulfone)s are engineering thermoplastics of potential commercial interest for film, fiber, molding, and composite applications because of their high glass transition temperatures and chemical resistance.
General processes for the production of poly(arylene sulfide sulfone)s are known. Poly(arylene sulfide sulfone)s can be prepared by the reaction of a polyhaloaromatic sulfone, such as bis(4-chlorophenyl)sulfone, with an alkali metal sulfide in the presence of a polar organic compound.
U.S. Pat. No. 4,016,145 discloses the use of alkali metal carboxylate and U.S. Pat. No. 4,127,713 discloses the use of sodium carboxylate to increase the molecular weight of poly(arylene sulfide sulfone)s. Although these patents represent significant and valuable advances in the art, there is a need for a process which can provide high molecular weight poly(arylene sulfide sulfone)s without the problems associated with handling alkali metal carboxylate. For example, use of aqueous alkali metal carboxylate solutions as a feedstock in the preparation of poly(arylene sulfide sulfone)s necessitates storing and handling a large volume of liquid to enable charging the desired amount of alkali metal carboxylate. Similarly, use of solid alkali metal carboxylate as a feedstock in the preparation of poly(arylene sulfide sulfone)s necessitates storing and handling a solid to enable charging the desired amount of alkali metal carboxylate. It has now been discovered that unexpectedly good results can be obtained using alkali metal carboxylate prepared in-situ by contacting a carboxylic acid with an alkali metal hydroxide in the production of poly(arylene sulfide sulfone)s.